Dust determinator



F. P. ANDERSON DUST DETERMI NATOR Filed March 24. 1923 4 Sheets-Sheet 1F P Andaraom 1,517,144 F. P. ANDERSON DUST DETERMINATOR Filed March 24,1.923 4 Sheets-Sheet I nvelrvlzor F. P. ANDERSON DUST DETERMINATOR FiledMatch 24. 1923 4 Sheets-Sheet 3 K v lnv e NE 39 v 35 40 F F? AruiwrsowF. P ANDERSON DUST DETERMINATOR Fild March 24 1923 4 Sheets-Sheet 4@(gAL 7 I 26 i .25 1 Z7 24 0 a j W 20 MOTOR FAN 1 1 Y F P AmcZarso/U m Aawme s Y nnsr nnv a ram, 'Annnnson; or rnxnva'rori, a

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' Application filed March 24, was. Serial it. 02mm.

To. all. may concern:

Be it known that I, FREDERICK PAUL ANDERSON, a citizenjof the UnitedStates,

residing at Lexington, in the county of t Fayette and Stateof Kentucky,have invented certain new and useful Improvements in Dust Determinators;and I; do hereby declare the followingtobe a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertamstolmake and use the same.

The resent invention relates to improve ments 1n dust determinatorsandrefers to an instrument for detecting the presence of dust and. otherforeign matter in the atmosphere.

Up to the present timethere has been no simple and accurate means ofmeasuring the amounts of dust or forelgn mater al n the air. All of themethods which. have been usedgive only relative results and the va--rious methods do not :check each other. They require a skilled scientistto make the estimates and a long, tedious laboratory analysis isnecessary. A large factor of error is induced by .the personality of theoperator. 1

It is an object of the present invention to to provide a simpleapparatus susceptible of use by a layman without .suflicienttraining inwhich the results are obtainable without intermediate calculation andanalysis, these results being shown on scales provided in at conjunctionwith the apparatus. Tests show that the apparatus will check previousresults, and both relative and absolute values can be obtainedwith it.

With the foregoing and other objects in W view, the inventlonwillbe more"fully ides scribed hereinafter, and will be more particularly pointedout in the claims'appended' hereto. 1

Figure 1 is a top plan view of theappara;

tnscons'tructed' according to the present in vention with the cover"-all let down. t I

Figure 2 is a 'side'viewof the same. re 3 is anend view with the coverfted and the side In the drawings, wherein like symbolsand theahingedside wall in closed 'ret ed-thereacross l d W? Figure 1adiagrammaticjview show-U mg the relative arrangement of the variousparts; 4

' Referrin first-to this diagrammatic view shown in igure 4, 5desiatesan electric motor, theshaft 6of whic I is connectfl by W thecoupling 7 to the shaft8 of alien 9.

The fan exhaust is shown at 10 andthej pi e. or conduit 11 connects withthe eye or in e of theifan. j i

At "a pointadjacfent the fan 9, isaninlet. W plpe 12 connecting withthecond'uitll and" m communication with the atmosphere. The inlet 12 isunder the control of a hand operated valve 13. The conduit is coupled toan air flow meter nozzlelt or ratherthe airflowmeter nozzle iscou leddirectly .in-- the conduit. Tubes'15. an 16,

preferably of a flexible characten'connect the conduit 11 atrespectively'opposite sides of thecai'r flow meter. nozzle with a gagewhich includes a U-sh'a ed tube17 mounted upon a scale 18. .Withm theU-shaped tube is a vli uid as shown adapted to he dis-n placed y thedifi'erential pressure of the air at o posite sides of then'ozzle 14:This deflection of the liquid column inthe tube coo crates with thegraduations' u on the sea e 18 to show accurately justfw at the pressureof the air is. The conduit ll-is provided with an elbow 19 just beyondthe st connection of the conduit with the tube 16 and this elbow '19connects with the hollow shank 20uponthe lower section 21 of the testfilter frame.

Thislower section 21 is made in the form cc of a truncated cone in,inverted position and on the lower section and above the-flange isadapted to receive the dia hragm 27 of filter material which is 'helbetween the fla g s and stretched across the widest portion or the testfilter frame. The upper part of the upper section 25 leads into areduced 'nec k 281 which is provided with threads for 'reinovably;receiving a an extension-inverted frustoconical filter frame $91.

havin a diaphra 300i .filter material to the upper end of the member 29.This diaphragrnfit) communicates directly with the outside atmosphere orwith theindoor atmosphere of a room or factory wherein the presenceof'dust or foreign matter .is to be determined. I

' The shank and the neck 28" are connected respectively by tubes 32 and33 with a second gage of which 34 represents the U tube and35 thegraduated strip cooperatingwiththe'fiuid in the U tube which is v theshank and neck. Y a

displaced by, the differential pressures Nowgthe "parts j] st describedare adapted for convenience injtransportation and use of the device to,be contained within a box like ,holder .havingthe base or: bottom 35,the end wallsf36 and 37', the'fixed side wall- 38 a nd the hingedsidewall 39. The side wall :39. swings' about the hinges indicated at 40invliigur'e 3;.and thetop or cover '41 of the device is likewise hinged asindicated at 42 ,to"the.end1wall 36. The coveris' pro vided with a'hasp43 adapt'ed'to cooperate with a staple or eye 44 upon the endwall 3 7 a.-padlo'ck b ing "adapted to be passed through the staple in orderjtolock the cover in .place. Incidentally this locking of the cover alsolocks'theisidewall 39, inasmuch as the sidewall is provided with clips45 pivotedupon theinterior. thereof as indicated .atL'4G -Land Inearthef'u'pper edge," such clips having oifiset endsf47 adapted toensgagewithin the upper tie rod 48 which is connected betweenfthe end walls'36and 37 These walls. arealso connected by a tie rod 49'-near'the- .bott01 or base. These tie rods reinforce and strengthen the holderorcontainer at the open side when the wall 39 95'- is swung.- down'asindicated in Figure 1.

. This wall maycontain'a chart 5.0 or a frame of, brass or othermaterial to hold sheets showing the calibrationcurve, etc. The cover 41isalso provided withsuitable bracest5lg' for admitting of the closing ofthe 'cover rbut adapted to hold said cover in an upright -'position,.itbeing 'understood that the cover carries "the two. gagesfas clearlyshown-in. Figure 3. 1 With the cover assumingthe upright position, thegages'may be accurately and clearly' read and in this ver- 'ticalposition they will render a faithful and ireliable record. i

- ;The and "wall-1,37 is" provided with a handle 52 ,for couvenienceinflcarrying the device whenr-thez cover and sidewall are closed.

The motor and the fan-ar e'mounted in appropriate supports. or uponappropriate pedestals .withinthe container and upon the base, and thefilter frame and its extenison this neck.

vided upon the base 35 to grasp the flanges of this; extension member 29as shown in Figure-1.

In a likemanner the upper section 25 of the filter-frame is removed byunscrewing movement or rattling of the parts.

The use of the device will be betterunderstood from reference to Figure4. The electric motor 5 being put in operation, the shafts 6 and 8 arerotatedand the fan 9 is put in motion. As a consequence air is drawninvthrough' the conduit 11 and exhausted throu h the outlet 10. The fanthus serves to raw in air both through the extension filter frame 29 andthrough the inlet 12, it being understood that at the start of the test,the valve 13. is open at least partially. By a proper manipulation ofthis valve 13 more or less air may be allowed to enter through theinlet-12' and proportionately to the air entering at this point will thesuction be diminished through thefilter-frame; The diaphragm 30 ispreferably composed of three ly' of chemical filter paper whichcleansftiie air before it enters the extension funnel 29; This clean airis allowed to pass through the apparatus until an 'equilibrlumofvapor-pressures between the air and filter medium isj-established.Then this extension funnel 29 is removed by unscrewing from the neck 28and the test proceeds as follows The air is now drawn in directly to theneck 28 and the valve 13 is resorted to to control the amount of airdrawn in through The air drawn in at 28 passes through the filter medium27 and then through the reduced shank 20 -to the conduit -11. The filtermedium or diaphragm 27 will absorb moisture from the air or give upmoisture to the air until there is a balance between the'vapor ressure.of the air and the vaporpressure o the filter medium. I This absorptionor giving up of moisture will varythe resistance of the filter medium.For this reason the auxiliary filter or extension funnel 29 is usedat'the intake. to allow onlyclean air to pass through the filter mediumuntil a balance of vapor pressure is. established. Now. the staticpressure in the air line acting through the neck 28 and tube 33 willtend toush the liquid down the leftleg of the U tu e 34, while thestatic pressure inthe air line acting. through the reduced tubular shank20 and the tube 32 will have a contrary effect on the liquid in thissame gage. I the static pressures on each side of the filter medium 27are ill) . emma filter medium 27, thefstatic pressure at the neck 28 isgreater than-the static pressure at "the 'shank' 20. The difierencesofthe static pressures will produce a difl'erence in level oftheliquids 1n'the'tube" legs. The

difference in level of the liquid in the gage indicatestheresistanceof'the filter medium. If the resistance of the medium stayscon-- stant,the volume of airdrawnthrough the medium is constant and thedifieren ces in levels of the liquidwill remain constant.

During the test the volume of air drawn through the filter medium isheld constant, and if there is "forei "material in this air itwillcollect on the lter medium,changing the resistance of, the filtermedium, and this change will be indicated by the' increase in' thedifferences of the levels of the liquids-in the U tube gage.

The nozzle '14- also restricts the flow of.

air in the conduit 11 and conse uently the pressure is greater where thetu e l6"connects "with the conduit than it isat the-oppositefside of thenozzle and this difierencein pressures is .also'controlled by the amountof air moving through the filter medium 27. The volume of air assingthrough the cenduitand through the filter frame will thus be registeredby the companion gage 17. The total air drawn in through the filterframe and through the inlet 12 passes to the fan 9 and is dischar ed at10.

The data taken uring a test ives the amount of air passed throu h thelter medium shown upon the gage 1 the resistance of the filter medium atthe start, and at equal time intervals during the test this pressuredifi'erence being shown by the gage 34 and the length'of time of thetest is also taken into account.

Referring to calibrated curves on the kind of dust deposited, the totalWeight of dust correspondmg' to the obtained increase in filterresistance is determined. Dividing the total weight of dust by the totalvolume of air passe through the filter, the weight of dust per unitvolume of air is obtained.

The filter medium may be compared to a scale of colors for relativevalues of dustiness. The filter medium contains the foreign mattercollected from the air and can be used for laboratory analysis;

The use of the term foreign matter in the claims is to be understood asreferring to any solid or liquid particles suspended in the air.

It is obvious that various changes and modifications may be made inthedetails of construction and design of the'above spe cificallydescribed embodiment of this invention without departing from the spiritthereof, changes and modifications being restricted only claims-: Y

is claimed is y the scope of the following 1. A dust determinatorcomprising a filter medium, means for maintaining a constant flow of airthrough sad filter medium, and means for measuringthe pressuredifierence across the filter medium. i

'2. A dust determinator comprising an enclosed filtermedium, means-fordrawing air from the atmosphere through said filter medium whereby to"deposit foreign matter from the air on said filter medium andthus checkthe flow of air" therethrough, and

means connected at opposite sides of said filter medium for indicatingthepressure difference across the filter medium.

'3.'A dust determinator comprising a fil-r ter medium, means-for mantaining a conthe current of air drawn in by the fanthrough said filtermedium, a pressure gage, an air flow meter positioned to receive the airafter passing through said filter medium,

and, means connecting the pressure gage to opposite sides of said filtermedium.

5. A dust determinator comprising a filter medium, a fan having itsinlet commuthe pressure under.

nicating with said filter medium and directly with the atmosphere, meansfor regulating the flow of air directly from the atmosphere to said fan,a pressure gage for" showi the difference in pressures across said fiter medium and an air flow. meter.

receiving the air after passage through said filter medium 6. A dustdeterminator comprising a filter frame, a. filter medium therein, apressure gage having connections to said filter frame at o posite sidesof the filter medium, an air ow meter connected to said filter frame,and a source of suction connectionto said air flow meter and to thefilter frame.

'7. A dust'determinator comprisinga filter frame having reduced ends andan enla ed central portion, afilter' medium stretc ed across theenlarged central portion, a pressure gage having 0 posite rts connectwto the reduced ends 0 said filter frame.

' 8. A dust determinator comprising a filter said lter frame, and- :asource of suction 1n communlcatlon with its : Y #10. Ajdust.deterxninator comprisin a thesectio ns, apressuregage connected tothereduced portions of said sections, and

sections having their larger ends fitted together, a, filter medium,stretched between means for creating a suction ofair throughsaidirsections and filter medium.

9. A dust determinator comprismga filter frame provided with an inletand an outlet andqhavingafil ter medium therein, a pressure gageconnected across said filter medium, an, extension frame; removably:con-

nected-to the inletrend of said filter frame and havingta filter mediumtherein, and a sourceof suction connected to the outlet of saidfilterframe. r

filter frame provided with an inlet and 'an outlet and having a filtermedium stretched thereacross, a pressure gage connected across, 20

said filtermedium, an extension filter frame having a filter mediumtherein and removably. connected to the inlet of said ,filter frame, aconduit connectingwith the outlet of said filter frame, a flow meter insaidconduit, aninlet to said conduit fromthe "atmosphere a" valve in theconduit, inlet,

and a source'ofsuction connected with the.

conduit. I.

'1'1.= :A dust determinator comprisin a casing having afhinged sideand-a hinge cover,

f means for securing said cover and side in .place pressure and flow.-meter gages carried y said cover, means for creating suction carriedwithin said casing, a filter frame adapted to be carried Within saidcasing and including a removable section and a removable extensionframe, means for connecting said filter frame with the pressure gages,means connected with the source of suction and filter frame, to checkthe flow, the flow meter gage being connected across said means, andmeans tor regulating the amount of air drawn through said Vfilter frame.a v

12. The method for determining the amount of foreign matter suspended ina unit volume of air, whichconsists in drawing air under pressurethrough a filter meair, which consists in creating a flow under pressureof air through a filter medium whereby to deposit foreignmatter upon themedium which proportionately I'BSlStS the flow-of air therethrough,taking the pressure difi'erence across said medium, and taking the rateof flow of air through the filter medium. i

I FREDERICK'PAUL-ANDERSON.

